A Fatal Case of Nocardia Bacteremia in a Lung Transplant Recipient

Abstract

<h3>Introduction</h3> <i>Nocardia</i> bacteremia is an extremely rare disease. Although closely associated with immunocompromised states, only a few cases have been reported after lung transplant (LT). <h3>Case Report</h3> We present a case of <i>Nocardia</i> bacteremia in a 75-year-old man after bilateral LT (11/2017) for combined pulmonary fibrosis and emphysema. Nearing 3 years posttransplant, pulmonary function tests (PFTs) revealed an obstructive pattern with downtrending FEV₁ from baseline; work-up for acute cellular rejection, infection, and antibody-mediated rejection was unremarkable. Serial PFTs ultimately suggested CLAD-BOS phenotype, and he received photopheresis with some stabilization. However, over the next 2 months, he required 2 hospital admissions with need for high-dose intravenous steroids given hypercapnia in the setting of underlying rejection. At 38 months posttransplant, he developed lower extremity cellulitis and new-onset anorexia, generalized weakness, and rapid decline in mental status with need for a third hospitalization and mechanical ventilation with vasopressor support. Infectious work-up and empiric broad-spectrum antibiotic coverage were initiated. Within 12 hours, both blood cultures were positive for <i>Nocardia cyriacigeorgica</i> (Gram stain, <b>Figure A</b>). Meropenem and trimethoprim/sulfamethoxazole were substituted without clinical improvement over the next several days. Brain MRI ruled out cerebral nocardiosis; chest CT showed bibasilar consolidations with air space opacities. An echocardiogram estimated a left ventricular ejection fraction between 20-25% with severe diffuse hypokinesis, likely stress-induced cardiomyopathy, with no evidence of vegetations. Bronchoscopy revealed superinfection with pan-sensitive <i>Pseudomonas</i> spp, without isolation of <i>Nocardia</i> spp. The patient deteriorated and died 39 months after transplant. <h3>Summary</h3> <i>Nocardia</i> bacteremia, scarcely reported in LT recipients, portends a poor prognosis despite aggressive combination antimicrobial therapy.